Electrode assembly for neon type and other luminous tubes



May 27, 1941- B. A. BOORE ELECTRODE ASSEMBLY FOR NEON TYPE AND OTHER LUMINOUS TUBES Filed Oct. 21, 1939 7 Burton 4. Boore V ii d Patented May 27, 1941 UNITED STATES PATENT OFFICE mac-non: MY ronrlnou'rm AND o'rm LUIINOUS runs Burton A. Boore, Han-Burg, Pa.

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vthe characteristics of Usalite porcelain and adapted to fit closely the interior oi a neon or other tube, and capable oi supporting the electrode co-axially within the tube, and of eilectually preventing the electrode from coming in contact with the tube and of cracking, puncturing or otherwise injuring the same.

It is also an object of the invention to provide an electrode assembly having an insulating ring slidably interlocked with the electrode and adapted to keep the gas back from the exterior of the electrode and thereby assist in maintaining a relatively cool condition oi the electrode at all times.

Another object of the invention is to eq ip the electrode with a supporting insulating ring maintained in proper position with relation to the tube and the electrode by spaced grooves and projections slldable therein, whereby the insulating ring will be movable at all times with the gas pressure.

With these and other objects in view, the invention consists in the construction and novel combination and arrangement of parts hereinafter fully described. illustrated in the accompanying drawing and pointed out in the claims hereto appended, it being understood that various changes in the form, proportion and minor details of construction, within the scope oi the claims, may be resorted to without departing from the spirit or sacrificing any 01' the advantages oi the invention.

In the drawing- Fig. l is a side elevation of an electrode assembly constructed in accordance with this invention and shown applied to one end of a luminous tube.

Fig. 2 is a central longitudinal sectional view oi the same.

Fig. 8 is a detail perspective view of the electrode having the U-shaped lead wires spot welded to the closed end of the electrode.

Fig. 4 is a transverse sectional view taken on the line 4-4 of Fig. 1.

Fig. 5 a detail perspective view oi the insulating ring.

Fig. 6 is a detail view showing the U-shaped leadwiresclinchedtotheclosedendofthe electrode.

m. 7 is a detail sectional view on the line I'l oi Pig. 6.

'l'lg. 8 is a detail sectional view taken longitudinally oi the inner end of one side of an electrode illustrating another means tor forming .a stop for confining an insulating ring on the electrode.

In the accomllfl llnl drawing in which is illustrated the preferred embodiment oi the invention, the electrode assembly comprises in its construction an electrode I consisting o! a hollow cylindrical shell closed at the outer end by a rounded tapering end wall I and having its inner end open and provided in the exterior of its inner portion with opposite longitudinal grooves 4 formed by indenting the material of the shell exteriorly and receiving projections l extending inwardly from the inner edge l oi aninsulating ring I. The electrode may be constructed of any suitable material such as pure copper, pure nickel andsteel andtheclosed endhassecured to it by spot welding orother suitable means. U-shaped lead wires 0 which are sealed in the end I of a luminous tube It in the usual manner.

In Figs. 1 to 3, inclusive, the lead wires 8 are spot welded to the closed rounded tapered end of the electrode and in Figs. 6 and 7 oi the drawing the electrode ll illustrated therein. is provided with an extension I! to which lead wires it are secured to the same by clinching the lead wires ll, the extension l2 being split for that purpose, as clearly illustrated in Fig. 'l of the drawing.

The longitudinal grooves I are substantially segmental in cross section and the projections I are substantially segmental to slidably lit the grooves and enable the insulating ring to move freely along the grooves with the gas pressure within the tube II to prevent spluttering of the electrode. The inner edge of the insulating sing I conforms to the configuration of and closely fits the exterior of the electrode and the outer edge or periphery of the ring fits closely the interior of the tube It so that the gas is excluded from the space back of the insulating ring, thereby maintaining the electrode in a comparatively cool condition and contributing materially to the length of the life of the electrode.

The insulating ring is preferably made of Usalite porcelain, a product of The Stupakofl Laboratories, Pittsburgh, Pennsylvania. Usalite material has substantially the same coefilcient oi expansion as the glass tube so that the glass trode.

' together and may be subjected to severe vibrations and abuse without any damage to the elec- The insulating ring supports and centers the electrode within the tube and eil'ectually prevents the electrode from coming in contact -with the tube which is thereby rendered puncture-prooi and is prevented from being broken or otherwise injured by reason of the electrode coming in contact with it.

The Usalite porcelain is a gas free material, thereby excluding gas from the insulating'ring' during the life of the electrode and at the same time preventing any deposits from accumulating on the walls of the glass tube. This also greatly contributes to long life of the electrode.

The insulating ring is confined on the inner portion of the electrode by the inner end walls ll of the longitudinal grooves and by protuberances i5 preferably formed in the grooves and located adjacent the inner end of the electrode.

The walls It limit the outward movement 01 the slidable insulating ring and the protuberances limit the inward movement of the ring with reference to the end of the tube so that the ring while being adapted to slide on the electrode with the gas pressure is effectually prevented from slipping off the end of the same. While any number of grooves I and projections 5 may, of course,

be employed two diametrically opposite grooves and projections will be found ample to maintain the ring in proper position with relation to the electrode and the tube. After the electrode assembly is arranged within the luminous tube and the lead wires sealed in the same, the tube is evacuated in the usual manner and the neon or other gas is introduced into the tube in the usual well known manner.

Each end of the tube is equipped with an electrode assembly and when a current is passed through the tube the gas becomes luminous. Neon gas or any other gas may be employed for providing a plain or colored lighting effect.

The segmental projections which extend from the inner edge of the insulating ring may be confined in the longitudinal grooves of the electrode by any suitable means, such as by flaring. slightly the groove at the terminal portion thereof as illustrated at I6 in Figure 8 of the drawing. This slight flaring of the terminal portion 01 the groove raises the bottom portion thereof and thereby forms a stop for preventing the protuberance of the insulating ring from leaving the groove. The groove may be distorted in any other suitable manner to confine the insulating ring on the electrode or any equivalent means may be employed for this purpose.

What is claimed is:

l. A luminous tube electrode assembly including a hollow cylindrical electrode having an outer rounded end wall and provided at its inner portion with an external longitudinal groove extending inwardly a relatively short distance from the inner end of the electrode, lead wires secured to the end wall of the electrode and adapted to be sealed into an end oi a luminous tube, and an insulating ring slidably arranged on the inner portion or the electrode and fitting the interior oi the luminous tube and supporting the electrode co-axially within the same, said insulating ring having at its inner edge a projection slidably fitting said longitudinal groove and preventing rotation of the ring on the inner portion 01' the electrode.

2. A luminous tube electrode assembly including a hollow cylindrical electrode having'an outer end wall and provided at its inner portion with an external longitudinal groove substantially segmental in cross section and extending inward- 1y a relatively short distance from the inner end oi the electrode, lead wires secured to the end wall of the electrode and adapted to be sealed in an end of a luminous tube, and an insulating ring arranged on the electrode and closely fitting the same and the interior of the tube and supporting the electrode co-axially within the tube, said ring being provided at its inner edge with a substantially segmental lug slidably fitting the groove and preventing rotation of the ring on the inner portion of the electrode.

3. A luminous tube electrode assembly including a hollow cylindrical electrode having an outer end wall and provided at its inner portion with an exterior longitudinal groove extending inwardly a relatively short distance from the inner end of the electrode, and an insulating ring arranged on the inner portion of the electrode and fitting the same and the interior of the luminous tube and supporting the electrode co-axially within the tube, said ring being provided at its inner edge with a projection slida-bly fitting the said groove, and a protuberance extending from the inner portion of the electrode and arranged to be engaged by the insulating ring for retaining the ring on the electrode.

4. A luminous tube electrode assembly including a hollow cylindrical electrode having an outer rounded end wall and provided at its inner portion with an external longitudinal groove extending inwardly a relatively short distance from the inner end or the electrode, lead wires secured to the end wall of the electrode and adapted to be sealed into an end of a luminous tube, and an insulating ring arranged on the inner portion of the electrode and fitting the interior of the luminous tube and supporting the electrode coaxially within the same, said insulating ring having at its inner edge a projection slidably fitting said longitudinal groove, and said electrode having said groove flared at the inner end of the electrode to form a stop for confining the insulating ring on the electrode.

BURTON A. BOORE. 

